Sewing thread



Nov. 6, 1934. A 0 w PETERSON 1,979,343

SEWING THREAD Filed June 8, 1953 Q a M cw has worrzeys- Patented Nov. 6, 1934 W UNITED STATES PATENT OFFICE SEWING THREAD s Oscar W. Peterson, Wollaston, Mass, assignor to Providence Braid Company, Pawtucket, R. I., a

corporation of Rhode Island Application June 8, 1933, Serial No. 674,880

' 6 Claims. (01. 96- 26) This invention pertains to sewing thread a and more particularlyto braided thread such as is now extensively used in attaching soles to shoes. Forthe above purpose, braided'thread has certain marked advantages over ordinary twisted thread. For example, it does not strand, when one of its constituentyarns is broken, for instance when the thread isstabbed byithe needle point, and thus itis possible 110 1158 a thread of a diameter substantially as large as thatof the awl hole; it is capable of taking up a large amount of lubricator or of wax which penetrates into its entire substance, thus firmly binding its constituent yarns together and helping to protect the thread from the weakening effects of moisture, etc. and it isgfree from unbalanced twist so that when drawn off from the threadfpackage and passed through the various guides of the sewing machine on its way to the needle it does not kink and twist, or producefimperfect work as is often the case when twisted thread is used. l-Iowever, it has been .fo'und-that when braided cotton thread is used in a machine provided with .thread waxing devices (as is common incertain typesof outer sole sewing machinelfthebraided cotton thread takes up so much wax that itoffers great resistance to pulling it through the'Twork, and as cotton thread is quite elastic, it is thus almost impossible to set up thejstitches so as to make a. tight seam unless the tension on the thread be so great as to cause excessive cutting and breakage during sewing. f a a f To avoid the above difiicult'y, experiments were made with braided linen thread, based upon the prevalent, belief that linen is superior in all respects to cotton, and at first the substitution of thismaterial for cotton appeared "to have solved the problem, since the braided linen, being less elastic and of higher tensile strength than cotton, could be set up to form vatight seam-even though fully impregnated with lubricator or wax, without abnormal breakage during sewing. However, it was soon found that shoes sewed with this linen thread didnot last so long in use as those sewn with cotton thread,-the stitches breaking after a short period of use, particularly in those parts of a shoe, for example, the shank portions, where there is a considerable amount of flexing of the shoe material. Further experimentation and investigation has shownit to be true,; that in general, linen thread, when subjected to conditions such as those encountered in shoeseams, is not nearly so durable or capable of resisting the weakening effects of moisture and repeated fiexure as is cotton. 1. v I have now discovered as the result of further experiment that sewing thread, particularly braided thread, in all respects well qualified for use. inmaking shoes, maybe made of a combination of linen and cotton in certain relative proportions and arrangements. When the linen and cotton are used in proper combination, I find that the thread, even though impregnated with lubricant or fully waxed, may be drawn down to form a tight seam without undue cutting and breaking in sewing and that, on the other hand, the stitches of the seam, after sewing, exhibit substantially the sameresistance to breakage when exposed to flexing, moisture, andrepeated strain in use as do stitches of cotton alone.

As herein used, the term braided thread is intended to cover not only a thread consisting solely of interbraided strands, but also one havmg. core consisting either of interbraided, intertwisted or parallel strands (or even a single strand) with an outer sheath or casing of interbraided strands. While as herein illustrated, the linen and cotton are assembled after each has been individually spun into strands or yarns, I contemplate the use of strands each comprising in itself the proper proportion of linen and cotton lfibefrgand in its broader aspects, the use of a combination oi linen and cotton in twisted as well as braided thread.

In the drawing, wherein I have illustrated oertain desirable embodiments of the invention by way of examplef- A Fig.1 is a fragmentary elevation showing one embodiment of the present invention in a tubular coreless braid,the braided structure being shown as diametrically expanded in order to illustrate more'clearly its structural characteristics;

Fig. 2 is a'section substantially on the line 2-2 of Fig.1; a a v ,Fig. 3 is a view similar to Fig. 1 but illustratin a modification comprising a tubular braid having a core; i v l a Fig. 4 is a section substantially on the line 44 of Fig. 3;

Fig. 5 is a section similar to Fig. 4 but illustrat ing a modification;

Fig. 6 is a fragmentary side elevation to large scale illustrating a twisted yarn of cotton and linen fibers usefulin making a thread in accordance with the present invention; and I Fig. 7 is a section, to smaller scale, showing a thread such as that of Fig. l, collapsed under longitudinal tension and fully waxed.

Referring to the drawing, the numeral 1 indicates the piece of braided thread according to the present invention, such thread being shown to greatly enlarged scale and comprising in combination strands 2 of cotton and strands 3 of linen or like physical characteristics. As here shown, this thread is a tubular braid consisting of sixteen ends or constituent strands of. which four are of linen and the remainder of'cotton, thus providing a sewing thread of approximately 75% cotton and 25%] linen. InFig. 7, this threadis shown in transverse section in the form it takes when subjected to longitudinal tension, and with its interstices filled with lubricant or hot wax W as it customarily is when ready to be drawn into stitches in shoe sewing.

Referring to Figs. 3 and 4, I have shown a cored tubular thread in which the outer jacket consists of interbraided strands 6, all of which are of cotton, this outer sheath or covering enclosing a centrally disposed core 5, here shown as a three cord twisted linen strand. In Fig. 4, for purposes of illustration, the outer covering is shown as spaced from the core, but in practice, when the thread is subjected to longitudinal tension,

the outer covering collapses into the core and when the thread is waxed, as is common in shoe sewing, the several parts are so united by the combined action of the wax and the frictional grip exerted by the sheath or covering upon the enclosed core, that the several constituent strand elements of the thread act substantially as a unit in resisting longitudinal stress.

In Fig. 5 I have illustrated a further modification in which the outer sheath consists of interbraided cotton strands 8 and linen strands .9, such sheath enclosing a core also consisting of interbraided cotton strands 10 and linen strands 11. In this arrangement the proportion of linen to cotton is substantially the same as in that shown in Figs. 1 and 2, whereas in the arrangement shown .in Fig. 3 the size of the core strands '7 is such as compared with the size of the yarns used in the sheath that the completed thread contains substantially 60% cotton and 40% linen.

Usually during the braiding operation the strands composing the thread are treated, as for example by passing them through size or other material adapted to providea smooth and finished surface. After braiding, the thread may undergo any of the usual finishing operations common in the art, all as desired.

While in the above description I have referred to the use of separate strands of cottonand linen in .making up the composite thread, I contemplate that similar results may be obtained by spinning each individual strand from a mixture of cotton and linen fibers in the proper portions. 'Thus in Fig. 6 I have illustrated such a thread 12 spun from fibers 13 of cotton and fibers 14 of linen, such fibers being prepared and blended in accordance with any usual method of fiber treatment and afterward spun into yarn in accordance with known methods of spinning. Such yarns may then be used in a braiding machine if desired for braiding a thread such as shown in Fig. 1, for example, but in this case all of the constituent yarns or strands making up the thread may be of like material.

In the following table there is shown the result of experimental comparison of twisted cotton thread, twisted linen thread, braided cotton thread, and thread made in acordance with the present invention ,-in particular as shown in Figs. 3 and 4 comprising interbraided strands of cotton and a linen core.

' Elongation Sample No. Yards per Breaking at time of lb. strength breaking l. 8 ed. twisted cotton. .l 841 63. 8 1.3 2. 8 cd. twisted linen 837 115. 0 1 3. Braided cotton 775 p 57.0 1. l 4. Braided cotton and linen 820 69. 4 .7

By reference to the above table it will be noted that the thread of combined linen and cotton, although of smaller size than the braided cotton, shows a decidedly higher breaking strength and a considerably lower elongation under breaking stress. This greater strength of the combined linen and cotton thread permits it to be set up to form a tight and firm seam in sewing shoes, even though the thread be impregnated with wax, although this is substantially impossible if braided thread consisting of cotton alone is employed, since the latter, if pulled down tight enough to set up a firm seam, breaks or is cut as it is drawn down over the bobbin thread.

On the other hand, the combined cotton and linen thread, when tested in actual use in shoes, is found far to outwear a thread of linen alone, even though the linen thread at the time of sewing possesses a much greater breaking strength than cotton of similar size, as illustrated by comparison of the twisted cotton and linen threads in the above table.

My experience leads me to believe that the proportion of cotton and linen for proper results should be of the order of from 20% to 50% linen and the remainder cotton, although preferably a somewhat greater per cent of linen is employed. For best results thus far obtained 40% of linen and 60% of cotton have been used, and I contemplate that this is substantially the proportion which will give the best results under most conditions of use.

While I have herein disclosed a braided thread having a sheath or covering consisting of sixteen ends or strands and in the case of the arrangement shown ,in Fig. 3 a core consisting of a three-core strand, I contemplate that the invention is not in any way limited to the exact number of strands employed either in the covering orin the core, but that any number or arrangement of strands may be used providing 115 the percentage of linen and cotton be kept substantially within the broad limits which I have found to be useful.

I claim:

1. A braided thread ready for use in sewing 120 shoemparts, said thread comprising strands of linen and strands of cotton, the interstices of the braided thread being filled with waX.

2. A thread ready for use in sewing shoes comprising a core of three-cord linen and a braided cotton cover, the interstices of the braid being substantially filled with hot wax.

3. A thread ready for use in sewing shoes comprising a core of linen and a braided cotton cover, the interstices of the braid being substantially filled with lubricant.

4. A thread of the class described comprising a plurality of braided strands, approximately three-fourths of said strands being of cotton and one-fourth being of linen, the interstices of the 5 thread being filled with wax.

5. A thread of the class described comprising a plurality of braided strands, approximately three-fourths of said strands being of cotton and one-fourth being of linen, the interstices of the thread being filled with lubricant.

6. A braided thread of the class described comprising inner and outer parts, one of said parts being a core and the other a sheath of interbraided strands, said thread comprising cotton and linen with the cotton in predominating proportion, and wax substantially filling the interstices of the thread.

OSCAR W. PETERSON. 

